const (
PA0 = portA + 0
PA1 = portA + 1
PA2 = portA + 2
PA3 = portA + 3
PA4 = portA + 4
PA5 = portA + 5
PA6 = portA + 6
PA7 = portA + 7
PA8 = portA + 8
PA9 = portA + 9
PA10 = portA + 10
PA11 = portA + 11
PA12 = portA + 12
PA13 = portA + 13
PA14 = portA + 14
PA15 = portA + 15
PB0 = portB + 0
PB1 = portB + 1
PB2 = portB + 2
PB3 = portB + 3
PB4 = portB + 4
PB5 = portB + 5
PB6 = portB + 6
PB7 = portB + 7
PB8 = portB + 8
PB9 = portB + 9
PB10 = portB + 10
PB11 = portB + 11
PB12 = portB + 12
PB13 = portB + 13
PB14 = portB + 14
PB15 = portB + 15
PC0 = portC + 0
PC1 = portC + 1
PC2 = portC + 2
PC3 = portC + 3
PC4 = portC + 4
PC5 = portC + 5
PC6 = portC + 6
PC7 = portC + 7
PC8 = portC + 8
PC9 = portC + 9
PC10 = portC + 10
PC11 = portC + 11
PC12 = portC + 12
PC13 = portC + 13
PC14 = portC + 14
PC15 = portC + 15
PD0 = portD + 0
PD1 = portD + 1
PD2 = portD + 2
PD3 = portD + 3
PD4 = portD + 4
PD5 = portD + 5
PD6 = portD + 6
PD7 = portD + 7
PD8 = portD + 8
PD9 = portD + 9
PD10 = portD + 10
PD11 = portD + 11
PD12 = portD + 12
PD13 = portD + 13
PD14 = portD + 14
PD15 = portD + 15
)
const (
LED = LED_BUILTIN
LED_BUILTIN = LED_GREEN
LED_GREEN = PA5
)
const (
BUTTON = BUTTON_USER
BUTTON_USER = PC13
)
const (
UART_TX_PIN = PA2
UART_RX_PIN = PA3
UART_ALT_TX_PIN = PD5
UART_ALT_RX_PIN = PD6
)
UART pins
const (
SPI0_SCK_PIN = PA5
SPI0_SDI_PIN = PA6
SPI0_SDO_PIN = PA7
)
SPI pins
const (
SCL_PIN = PB6
SDA_PIN = PB7
)
I2C pins
const (
TWI_FREQ_100KHZ = 100000
TWI_FREQ_400KHZ = 400000
)
TWI_FREQ is the I2C bus speed. Normally either 100 kHz, or 400 kHz for high-speed bus.
const NoPin = Pin(0xff)
NoPin explicitly indicates “not a pin”. Use this pin if you want to leave one of the pins in a peripheral unconfigured (if supported by the hardware).
const (
PinInput PinMode = 0 // Input mode
PinOutput10MHz PinMode = 1 // Output mode, max speed 10MHz
PinOutput2MHz PinMode = 2 // Output mode, max speed 2MHz
PinOutput50MHz PinMode = 3 // Output mode, max speed 50MHz
PinOutput PinMode = PinOutput2MHz
PinInputModeAnalog PinMode = 0 // Input analog mode
PinInputModeFloating PinMode = 4 // Input floating mode
PinInputModePullUpDown PinMode = 8 // Input pull up/down mode
PinInputModeReserved PinMode = 12 // Input mode (reserved)
PinOutputModeGPPushPull PinMode = 0 // Output mode general purpose push/pull
PinOutputModeGPOpenDrain PinMode = 4 // Output mode general purpose open drain
PinOutputModeAltPushPull PinMode = 8 // Output mode alt. purpose push/pull
PinOutputModeAltOpenDrain PinMode = 12 // Output mode alt. purpose open drain
)
const (
Mode0 = 0
Mode1 = 1
Mode2 = 2
Mode3 = 3
)
SPI phase and polarity configs CPOL and CPHA
var (
// USART2 is the hardware serial port connected to the onboard ST-LINK
// debugger to be exposed as virtual COM port over USB on Nucleo boards.
// Both UART0 and UART1 refer to USART2.
UART0 = UART{
Buffer: NewRingBuffer(),
Bus: stm32.USART2,
}
UART2 = &UART0
)
var (
ErrInvalidInputPin = errors.New("machine: invalid input pin")
ErrInvalidOutputPin = errors.New("machine: invalid output pin")
ErrInvalidClockPin = errors.New("machine: invalid clock pin")
ErrInvalidDataPin = errors.New("machine: invalid data pin")
ErrNoPinChangeChannel = errors.New("machine: no channel available for pin interrupt")
)
var (
SPI1 = SPI{Bus: stm32.SPI1}
SPI0 = SPI1
)
There are 3 SPI interfaces on the STM32F103xx. Since the first interface is named SPI1, both SPI0 and SPI1 refer to SPI1. TODO: implement SPI2 and SPI3.
var (
I2C1 = I2C{Bus: stm32.I2C1}
I2C0 = I2C1
)
There are 2 I2C interfaces on the STM32F103xx. Since the first interface is named I2C1, both I2C0 and I2C1 refer to I2C1. TODO: implement I2C2.
var (
ErrTxInvalidSliceSize = errors.New("SPI write and read slices must be same size")
)
func CPUFrequency() uint32
func NewRingBuffer() *RingBuffer
NewRingBuffer returns a new ring buffer.
type ADC struct {
Pin Pin
}
type I2C struct {
Bus *stm32.I2C_Type
}
func (i2c I2C) Configure(config I2CConfig)
Configure is intended to setup the I2C interface.
func (i2c I2C) ReadRegister(address uint8, register uint8, data []byte) error
ReadRegister transmits the register, restarts the connection as a read operation, and reads the response.
Many I2C-compatible devices are organized in terms of registers. This method is a shortcut to easily read such registers. Also, it only works for devices with 7-bit addresses, which is the vast majority.
func (i2c I2C) Tx(addr uint16, w, r []byte) error
Tx does a single I2C transaction at the specified address. It clocks out the given address, writes the bytes in w, reads back len® bytes and stores them in r, and generates a stop condition on the bus.
func (i2c I2C) WriteByte(data byte) error
WriteByte writes a single byte to the I2C bus.
func (i2c I2C) WriteRegister(address uint8, register uint8, data []byte) error
WriteRegister transmits first the register and then the data to the peripheral device.
Many I2C-compatible devices are organized in terms of registers. This method is a shortcut to easily write to such registers. Also, it only works for devices with 7-bit addresses, which is the vast majority.
type I2CConfig struct {
Frequency uint32
SCL Pin
SDA Pin
}
I2CConfig is used to store config info for I2C.
type PWM struct {
Pin Pin
}
type Pin uint8
Pin is a single pin on a chip, which may be connected to other hardware devices. It can either be used directly as GPIO pin or it can be used in other peripherals like ADC, I2C, etc.
func (p Pin) Configure(config PinConfig)
Configure this pin with the given I/O settings. stm32f1xx uses different technique for setting the GPIO pins than the stm32f407
func (p Pin) Get() bool
Get returns the current value of a GPIO pin.
func (p Pin) High()
High sets this GPIO pin to high, assuming it has been configured as an output pin. It is hardware dependent (and often undefined) what happens if you set a pin to high that is not configured as an output pin.
func (p Pin) Low()
Low sets this GPIO pin to low, assuming it has been configured as an output pin. It is hardware dependent (and often undefined) what happens if you set a pin to low that is not configured as an output pin.
func (p Pin) Set(high bool)
Set the pin to high or low. Warning: only use this on an output pin!
type PinConfig struct {
Mode PinMode
}
type PinMode uint8
type RingBuffer struct {
rxbuffer [bufferSize]volatile.Register8
head volatile.Register8
tail volatile.Register8
}
RingBuffer is ring buffer implementation inspired by post at https://www.embeddedrelated.com/showthread/comp.arch.embedded/77084-1.php
func (rb *RingBuffer) Clear()
Clear resets the head and tail pointer to zero.
func (rb *RingBuffer) Get() (byte, bool)
Get returns a byte from the buffer. If the buffer is empty, the method will return a false as the second value.
func (rb *RingBuffer) Put(val byte) bool
Put stores a byte in the buffer. If the buffer is already full, the method will return false.
func (rb *RingBuffer) Used() uint8
Used returns how many bytes in buffer have been used.
type SPI struct {
Bus *stm32.SPI_Type
}
func (spi SPI) Configure(config SPIConfig)
Configure is intended to setup the STM32 SPI1 interface. Features still TODO: - support SPI2 and SPI3 - allow setting data size to 16 bits? - allow setting direction in HW for additional optimization? - hardware SS pin?
func (spi SPI) Transfer(w byte) (byte, error)
Transfer writes/reads a single byte using the SPI interface.
func (spi SPI) Tx(w, r []byte) error
Tx handles read/write operation for SPI interface. Since SPI is a syncronous write/read interface, there must always be the same number of bytes written as bytes read. The Tx method knows about this, and offers a few different ways of calling it.
This form sends the bytes in tx buffer, putting the resulting bytes read into the rx buffer. Note that the tx and rx buffers must be the same size:
spi.Tx(tx, rx)
This form sends the tx buffer, ignoring the result. Useful for sending “commands” that return zeros until all the bytes in the command packet have been received:
spi.Tx(tx, nil)
This form sends zeros, putting the result into the rx buffer. Good for reading a “result packet”:
spi.Tx(nil, rx)
type SPIConfig struct {
Frequency uint32
SCK Pin
SDO Pin
SDI Pin
LSBFirst bool
Mode uint8
}
SPIConfig is used to store config info for SPI.
type UART struct {
Buffer *RingBuffer
Bus *stm32.USART_Type
Interrupt interrupt.Interrupt
}
UART representation
func (uart UART) Buffered() int
Buffered returns the number of bytes currently stored in the RX buffer.
func (uart UART) Configure(config UARTConfig)
Configure the UART.
func (uart UART) Read(data []byte) (n int, err error)
Read from the RX buffer.
func (uart UART) ReadByte() (byte, error)
ReadByte reads a single byte from the RX buffer. If there is no data in the buffer, returns an error.
func (uart UART) Receive(data byte)
Receive handles adding data to the UART’s data buffer. Usually called by the IRQ handler for a machine.
func (uart UART) SetBaudRate(br uint32)
SetBaudRate sets the communication speed for the UART. Defer to chip-specific routines for calculation
func (uart UART) Write(data []byte) (n int, err error)
Write data to the UART.
func (uart UART) WriteByte(c byte) error
WriteByte writes a byte of data to the UART.
type UARTConfig struct {
BaudRate uint32
TX Pin
RX Pin
}